Vessels and containers for storing or preparing liquid substances may be equipped with a sampling assembly, typically located in a sidewall of the vessel, by way of which a sample of the liquid can be extracted from the vessel without opening the same. There exist so called septum-based access assemblies, acting as a sampling assembly featuring a pierceable sealing member, typically denoted as septum. Such a septum is typically arranged in a passageway or in a through opening of a sampling assembly. The sealing member should provide a liquid- and gas-tight seal for the sampling assembly.
The pierceable sealing member typically comprises a polymeric, elastomeric or rubber-based material, which effectively seals the passageway extending through the sampling or access assembly. Moreover, the sealing member or the septum may be pierced by a tipped-cannula or by a respective needle assembly in such a way, that a free end of the cannula extends into the inner volume of the vessel in which the liquid substance is contained. If the cannula is for instance in fluid connection with a withdrawal device, such like a syringe a sample of the liquid can be extracted. Due to the elastic properties of the sealing member, the puncture of the sealing member can be effectively sealed after removal of the cannula or piercing member.
Depending on the overall geometry of the vessel, the medium contained therein and depending on the diameter or size of the sealing member, the sealing member may be subject to wear, e.g. when punctured or pierced multiple times. Therefore, the sealing member has to be replaced frequently. For a replacement of the sealing member it is typically necessary, that the vessel is substantially empty in order to prevent, that the content of the vessel gushes over an operator upon removal of the sealing member. This aspect is of extreme importance since the liquid medium stored in the container may comprise an acid or a comparably chemically aggressive liquid medium.
Moreover, conventional septum-based sampling or access assemblies may be provided with an additional closure, which is to be removed from a base of the sampling assembly to provide access to the pierceable sealing member located underneath. In situations, where the sealing member is not correctly mounted or when an inappropriate sealing member has been inadvertently used, removal of the outer closure may already lead to an uncontrolled discharge of the liquid medium into the environment.
It is therefore an object of the present invention to provide an improved access and/or sampling assembly that comes along with an enhanced security for an operator, both for extracting a probe as well as for replacing a pierceable sealing member. Moreover, it is a further aim to reduce a degree of potential contamination of the liquid medium located in the vessel during sample extraction. Additionally, the access assembly should be user friendly, both in terms of its general handling as well as in terms of cleaning the sampling assembly and/or the vessel, to which the access or sampling assembly is connected.
In another object, the access assembly should be adapted to provide clear and easily perceivable indicators to an operator in the event, that a malfunction of the access assembly is given, preferably without the danger, that the environment or the operator is contaminated with the content of the vessel to a large extend.